Hi John,
Welcome to the forum and welcome to the hobby.
Unfortunately, the kanji on the kogatana are a little worn and not done in the nice "blocky" fashion that is helpful to western readers, so I'm struggling with the fourth and sixth kanji,however, I think there's enough that I can make out to take a stab at it.
The first three kanji (志津三...) read "Shizu sa" and that is a combination that often comes up in a line of smiths signing "Shizu saboro Kane Uji". In this case there is also a "Minamoto" (源) thrown in so it might be this guy:
KANEUJI (兼氏), Kanbun (寛文, 1661-1673), Mino – “Shizu Saburō Minamoto Kaneuji” (志津三郎源兼氏), real name Tōyama Jinjūrō (遠山甚十郎), he lived in Ōgaki (大垣) in Mino province, by the shintō-era, the lineage of Kaneuji had split into the Ōgaki, Gifu (岐阜), and Seki branches that were locally active until the Meiji era, the Ōgaki line smiths bore the family name Tōyama and the Seki line smiths the family name Fukuchi (福地)
I say might, because for some reason manufacturers of kogatana often add a somewhat "aspirational" signature to them, usually of a famous smith, so this may not actually be the maker.
I hope that helps. If you get the time please also post some pictures of your new sword as we like looking at pictures of swords!
Kind regards,
another John